Abstract: Cu6Sn and Ni₃Sn₄ are important intermetallic compounds(IMCs), which were known to greatly improve the reliability of the soldered joints.In this paper, the first-principles calculations were performed to determine the stable structure of Cu₆Sn₅ and Ni₃Sn₄ IMCs.The structural and electronic properties of Cu₆Sn₅ and Ni₃Sn₄ IMCs were calculated.The results of energy calculation and density of states demonstrate that Cu₆Sn₅ IMCs have a more stable structure than Ni₃Sn₄.The results also show that they are exhibit anisotropy in elastic modulus.Moreover, the Ni₃Sn₄ shows more strong bonding effect and exhibits greater elastic modulus.However, Cu₆Sn₅ performs better in plastic, which is expected to account for the improvement in the reliability of the soldered joint.